public class Test {

    public static void main(String[] args) {
        BinaryTree binaryTree = new BinaryTree();
        /*为什么不是BinaryTree.TreeNode root = binaryTree.TreeNode();
        或者 binaryTree.TreeNode root = binaryTree.createTree();
        或者 binaryTree.TreeNode root = binaryTree.TreeNode();*/
        BinaryTree.TreeNode root = binaryTree.createTree();
    }
}
